is CXF Oauth2 Services can be used as Singleton ?

[Venkata Pavan Kumar Sannisetty]

Hi ,
I have configured CXF OAuth2 services such as AuthorizationCodeGrantService, 
ImplicitGrantService, AccessTokenService registered using spring configuration. 
While going through how to configure these services using spring XML i have 
found that the service beans which are referenced directly from the 
jaxrs:server endpoint declarations are treated by the runtime as singleton 
JAX-RS root resources.  
(http://cxf.apache.org/docs/jaxrs-services-configuration.html#JAXRSServicesConfiguration-JAXRSServicesConfiguration-FromSpring)
Example:
        <bean id="authCodeGrantService" 
class="org.apache.cxf.rs.security.oauth2.services.AuthorizationCodeGrantService"
 parent="redirectionBasedOAuth2Service">        </bean>         <bean 
id="implicitGrantService" 
class="org.apache.cxf.rs.security.oauth2.services.ImplicitGrantService" 
parent="redirectionBasedOAuth2Service"> </bean>
      <jaxrs:server id="oauthServer" address="/">               
<jaxrs:serviceBeans>                    <ref bean="authCodeGrantService"/>      
                <ref bean="implicitGrantService"/>              
</jaxrs:serviceBeans>           <jaxrs:providers>                       <ref 
bean="jsonProvider"/>              </jaxrs:providers>      </jaxrs:server>The 
above code snippet creates a singleton resources of both authCodeGrantService 
and implicitGrantService. But when looking at the source code of these two 
services i found these two services have been using MessageContext cxf class 
which is per request specific and it is used as a member variable in 
AbstractOAuthService. 
If MessageContext class is per request specific and it is a member variable the 
service can't be used as singleton. Please correct me if i am wrong as i am new 
to cxf.  AbstractOAuthservice is the baseclass for 
AuthorizationCodeGrantService, ImplicitGrantService, AccessTokenService and 
TokenRevocationService.
At the same time i have looked at the source code of 
AbstractAccessTokenValidator which is also using MessageContext as member 
variable but in the get method  it is a bit different.
public MessageContext getMessageContext() {        return mc != null ? mc : new 
MessageContextImpl(PhaseInterceptorChain.getCurrentMessage());    }
I just wanted to know whether these services can be used as singletons or not ? 
If this should a bug/enhancement please let me know so that i can flag for the 
same.
Thanks,Pavan.P.S: CXF Rocks